Biological control of Schistocerca gregaria and Locusta migratoria migratorioides using Entomopathogenic bacteria

Abstract

This study investigated the potential of indigenous entomopathogenic bacterial (EPB) strains from Egypt to control the two most prevalent locust species, Schistocerca gregaria (Forsskål) (Orthoptera: Acrididae), and Locusta migratoria migratorioides (Reiche & Fairmaire) (Orthoptera: Acrididae). To assess the efficacy of the EPB strains, experiments were conducted in the laboratory, semi field, and field. The results showed that Xenorhabdus nematophila (Thomas et Poinar) BA2 (Enterobacterales: Morganellaceae) and Photorhabdus luminescens (Thomas et Poinar) EGAP3 (Enterobacterales: Morganellaceae) were the most effective strains against S. gregaria and L. migratoria migratorioides in laboratory settings. Under semi-field conditions, X. nematophila BA2 recorded nymphal mortality rates of 89.31% and 85.00% against the 2nd and 5th nymph instars of S. gregaria, respectively, and P. luminescens EGAP3 showed nymphal mortality rates of 88.00% and 80.00% against the 2nd and 5th nymph instars of S. gregaria, respectively. In field trials, X. nematophila BA2 exhibited the highest nymphal mortality rate of 88.70% at 7 days after spraying. Overall, the findings of this study suggest that X. nematophila BA2 and P. luminescens EGAP3 are promising candidates for environment-friendly, safe locust pest management. Further research is needed to explore and develop these bacteria for commercial use in agriculture.